The present invention relates to a thermal transfer recording material. More particularly, it relates to a thermal transfer recording material useful for forming ink images having a smooth surface on a receptor having a porous surface layer.
Heretofore there was proposed a thermal transfer recording method using a thermal transfer recording material wherein a coated area of a heat-meltable ink and an uncoated area thereof are repeatedly arranged in a side-by-side relation on one side of a foundation. The method comprises: selectively transferring the heat-meltable ink of the coated area by means of a thermal head to form ink images on a receptor paper, superimposing the uncoated area of the ink on the recording material onto the image-bearing surface of the receptor paper, and heating the ink images by means of the thermal head to permit the ink of the images to penetrate voids between the fibers of the receptor paper, thereby giving ink images having excellent abrasion resistance and durability (Japanese Unexamined Patent Publication No. 103488/1989). Hereinafter this method is referred to as reheating method.
On the other hand, there was developed as a receptor for use with a thermal transfer recording material a receptor having a porous surface layer (hereinafter referred to as porous surface receptor) wherein a resinous layer having a large number of minute pores is formed on a film substrate (Japanese Unexamined Patent Publication No. 41287/1990).
Although the porous surface receptor has been subjected to a smoothing treatment in the production thereof, the surface of the receptor is still uneven and poor in smoothness. Accordingly, the ink image formed on the receptor has a uneven surface, which causes a diffused reflection, resulting in a low image density, or a poor color reproduction with respect to full-color image.
In order to settle the above problems, the present inventor has attempted to smooth the surface of the ink image formed on the porous surface receptor by applying the above-mentioned reheating method. However, in the reheating step, a phenomenon occurred that some portion of the ink of the images adheres to the uncoated area of the recording material transfer to the recording material. Hereinafter, the phenomenon is referred to as reverse transfer. The reverse transfer degrades the quality of the ink image.
It is an object of the present invention to provide a thermal transfer recording material for use in the aforesaid reheating method which does not cause the reverse transfer in the reheating step.
This and other objects of the present invention will become apparent from the description hereinafter.